Dynamo-electric machine.



V. A. PYNN" DYNAMO ELECTRIC MAHNE.

APPLICATION FILED Nov. 29, 1909i' 1,062,383. Patented seppia, 1911.

3 SHEETS-SHEET 1.

1J Fig. l. n

Fig. 3.

. CML Valre Aiynn.

- v' l H11/EY)` l l V. A. FYNN. DYNAMO ELEC1`RIC\MAGHINE.

APPLICATION FILED NOV.29.19o9.

Patented Sept. 5, 1911.

3 SHEETS-SHEET 2.

f/vvE/vroe Valre A. Fynn.

EYS

V. A. FYNN. DYNAMO ELECTRIC MACHINE. APPLICATION FILED 11017.29, 190e.

1,002,383.v A Patented Sept. 5, 1911.

3 SHEETS-SHEET 3.

vFigfl..

- UNITED sTATEs PATENT oEEIoE.

R y VALRE ALFRED FYNN, OF LONDON, ENGLAND, ASSIGNOR TO WAGNER. ELECTRICMANUFACTURING COMPANY, F ST. LOUIS, MISSOURI, A CORPORATION OF MIS`SOURI.

DYNAMO-ELECTRIC MACHINE.

Specification of Letters Patent.

Patented Sept.

Application led November 29, 1909. Serial No. 530,285.

To all whom't may concern:

Be it known that I, VALRE ALFRED FYNN, a subject of the Kinglof England,residing at London, England, have inventeda certain new and usefulDynamo Electric 'Machine, of which the following is such a full, clear,and exact description as will enable any one skilled in the art to whichit appertains to make and use the same, reference .being had to theaccompanying drawings, forming part of this specification.

My invention relates particularly to continuous current generators.

The objects are to provide a generator which will yield an E. M. F. of amagnitude independent of the speed at which the machine is driven and ofa constant direction independently of the direction of rot-ation.`

Such a machine 1slmore particularly intended to generate continuouscurrents for use in combination with'certain train light ing systems,for windmill operated plants and thef'like. In order to achieve theseobjects I provide a neutralized self-excited dynamo in which theexciting circuit is closed on itself and is at least partly disposed onthe rotor and in which the excitingE. M. F. is generated in said rotorby rotation in a magnetic field to which I wlll refer as the teaserflux. According to this invention I make the magnitude of said teaserflux dependent on thediil'erence of two E. M. Ffs,

' the smaller of these being an E. M. F. generated by the machine itselfand the other being an independent E. M. F. derived from any desiredsource. If this independent E. M. F. is ac'onstant ond then the maximumvariation'of the working E. M. F. generated in my machine, when drivenat any speed equal or superior to a given minimum speed, will not exceedthe E. M. F. which is required at the terminals of the teaser fluxproducing winding in order to allow the necessary exciting current to begenerated in the vshort-circuited field winding at the minimumspeed forwhich the machine is built. Thus if the maximumE. M. F.` required at theterminals of the teaser wind-` ing is one volt then the diHerencebetween the voltage generated in my dynamo when `running at its minimumspeed and when running at an infinitely great speed will also be onlyone volt provided the'independent E. M. F. included in the teasercircuit remains constant throughout. If the indel pendent E. M. F. ismade to vary to the extent of one volt increasing by that amount as thespeed decreases down to the minimum speed then the voltage generated inmy dy namo will remain constant throughout. To

whatever extent the independent E. M. F. is

caused to vary during the operation of the machine the E. M. F.generated in the d namo will never dider from the independent E. M. F.by more than the E. M. F. at the terminals of the teaser flux producingwinding. This E. M. F. can be reduced by reducing the resistance of theteaser flux producing winding and by decreasing the reluctance of themagnetic path provided for the teaser flux. For a given reluctance ofthe magnetic path and a given resistance of the teaser fiux producingwinding the E. M. F. required at the terminals of said winding willincrease with decreasing speed. For this reason it will be necessary tosettle on a minimum speed below which the machine should not be run. Ifit is run below that speed then the voltage generated in the ma-` chinewill drop rapidly, of course, becoming zero at standstill. The minimumspeed can, however, be chosen sufficiently low to satisfy all practicalrequirements. The independent E. M. F. can be so varied as to' at leastpartly compensate for the ohmic drop in the mains. The exciting E. M. F.being generated by the rotation of the rotor conductors inthe teaseriux, the direction of that E. M. F. will alter when the direction ofrotation is altered and the direction'of the working E. .M. F. willconsequently) be .the same for either direction of rotation.

In the accompanying drawings, `Figure 1 shows a simple form of thisinvention; Fig. 2 shows anotherl form of this dynamo, the independent E.M. F.being derived from a 4motor generator; Fig. `3 shows a' differentbrush arrangement and connections for utilizing the armature windingitself for pro- -ducing the teaser flux; Fig. 4 shows a way ofimpressing on the teaser winding a part only of t-he working E. M. F.generated in the main dynamo, and Fig. 5 indicates constructive featuresof such a dynamo.

Referring to Fig. l, the rotor carries by way of example two independentwindings 5 and 28 and the stator has two coaxial wind* ings 3 and 1l.The neutralizingwinding 3 is connected in series relation and inopposition to the rotor winding 5 along an axis approximately coincidingwith that of 3 and l constant. This smaller current is of course y Wayof the brushes 4 and G. Its ampere turns are preferably chosen a littlegreater than the rotor ampere turns along the axis 4, 6. This is theworking circuit of the dynamo. The rotor winding 28 is closed on itselfbyway of the brushes 7, 8; this is the exciting circuit of the machine.The teaser Winding 11 is connected across the mains 1, 2 and any desiredsource of E. M. F. such as the storage battery 31 is included in thecircuit of 11. This source produces the independent E. M. F. e2 and anecessary condition is that e, be connected in opposition to el, whichis the E. M. F. of the mains. Their resultant et.L produces the currenta through the teaser Winding 11. The respective directions of e2 and e,in the circuit containing 11 are indicated by the arrows 32, 33. In Fig.1 the exciting E. M. F. responsible for the exciting current isgenerated in 28 at the brushes 7, 8 and by rotation in the flux due to11.

In Fig. 2 is shown the preferred arrangement of circuits, the maindynamo being arranged to deliver three E. M. F.s, el, e8, anden, ofdiffering magnitude and all independent of the speed and also beingcapable of feeding a three-wire system of distribution. One Workingcircuit comprises the neutralizing Winding 3 and the rotor -Winding 5;the ampere turns in 3 can be regulated at 27 by means of the resistance26 shunting 3. The E. M. F. of this Working circuit is el. The oneexciting circuit comprises the rotor Winding 5 between the brushes 7, 8and the field Winding 9, disposed on the stator and preferably displacedfrom 3 by 180/n degrees, Where fn stands for the number of poles of theInachine. The ampere turns in 9 can be varied for instance, by varyingthe active number of turns in 9 at 10. The use of this additional fieldwinding makes it possible to reduce the magnitude of the excitingcurrent while retaining the same number of ampere turns therebyfacilitating commutation at the exciting brushes 7, 8. By revolution ofthe rotor conductors in the teaser flux an exciting E. M. F. isgenerated at the brushes 7, 8 and if those brushes are short-circuited acertain exciting current will flow inv the Winding The magnitude of thiscurrent will depend on the ohmic resistance of the shortecircuit as longas the exciting E. M. F remains constant. The exciting ampere turns willdepend on said current and on the. number of voltturns of the rotorWinding lf the number of exciting turns be doubled by including theWinding 9 between the brushes 7, 8, then the exciting current will bereduced. If the resistance of the exciting circuit has been doubled bythe addition of 9 then the exciting current will be halved, provided theexciting E. M. F. has remained easier to commutate and since it flows indouble the number of turns its magnetizing effect is the same as that ofthe larger current flowing in the winding 5 only. Since the excitingbrushes 7, 8 rest on the rotor winding which does duty as armature orworking Winding, then a conductor 0 connected at 40 yto any point of 9or to either of the exciting brushes will halve the potential betweenthe mains 1 and 2. Mains 1,

2, 0 can, therefore, be connected to a threewire system.

,The second Working circuit starts 'at main 42 and comprises a secondrotor Winding 28 connected in series relation With 5 by way of thebrushes 30, 29, 6, 4 and ends at main 41 after passing through 3. The E.M. F. e, due to 5 is, added to e8 due to 28,'resulting in the E. M. F.e, impressed on the mains 41, 42 which are thus fed quite independentlyof the mains 1, 2 and 0. A. fourth E. M. F. about equal to one-half oferi-e8 is also available between the mains O and 42. Translating devices57 are shown connected across the various differin but practicallyconstant potentials obtaina le from this dynamo.

The teaser flux is produced by the teaser winding 11 preferably disposedin the axis of 3. The teaser Winding is connected on one side to main 2near brush 6 and on the other to main 1 by way of switch 34 point 35,series exciting Winding 18 of the motor 14, brushes 22, 23 of dynamoarmature 21 and Wire 13. The dynamo 21 is driven by the shunt motor 14connected in parallel to the mains 1, 2. The shunt Winding 17 of themotor' is connected by Way of example in series With the shunt Winding24 of the dynamo 21y and across the mains 1, 2. As the load on thedynamo 21 increases owing 'to the larger current taken by 11 withdecreasing speed of the main machine, the speed of 14 is liable todiminish thus decreasing the independent E. M. F. e, generated by 21 andincluded in the teaser circuit in opposition to the E. M. F. e, derivedfrom the mains 1, 2. To avoid this, a field winding 18 has been disposedon motor 14 and so connected in series with 21 and 11 as to produce amagnetization opposed to that due to 17 thereby increasing the motorspeed. By this means it is possible to so vary e2 that e, Will remainpractically constant. `It is best to disconnect the main dynamo from thecircuit after its speed has reached that critical speed aty whichadequate control of-e1 becomes impossible by the means herein set forth.l

If the connections are such as shown in Fig. 2 then the auxiliary dynamo21 must generate an E. M. F. slightly greater than e, and must be ableto carry the maximum current required by 11.

In order to prevent an undue rush of current when connecting this noveldynamo to the translating devices, it is desirable to tirst bring it upto near the critical speed and to initiate the self-exciting process bytemporarily impressing on 1l an E. M. F. of suitable magnitude (aboutmaximum (5,) derived 4 from any desired source such as the primary orsecondary battery 37. This is achieved by moving switch 34 on to point36'. After the main dynamo has been connected to the mains and 14 and 2lare running, switch 34 can be moved on to point 35, thus reestablishingthe normal connections.

In Fig. 3 the brush arrangement` differs from the previous in that bothsets of brushes, 4, 6 and 7, 8 are displaced by 90/17 degrees from theaxis of 3, the sets ot brushes being displaced in opposite directionsfrom ,that axis. 6 is connected to 7 by way of the tield winding 9 and Sis counected to 4 by way of the field winding 9. Brushes G, 7 and 8, 4could be short-circuited in pairs as named. Those portions of 5 whichareA comprised between the brushes (S, 7 and 8, 4 do duty as fieldwinding,l the rest do duty as armature or working windings and areconnected lin series with the neutralizing winding 3 by Wayof points 38and 89 situated midway in the windings 9 and 9 respectively. Being thusconnected, the working current will flow through theield windings 9 and9 without producing any magnet-ization.

That. part of the rotor Winding which does duty as armature o1' workingwinding is in this case also made use of as teaser winding. To this endthe independent E. M. F. e2 derived from 31 is 'connected to the workingcircuit 'at the points 43 and 44and in opposition to the E. M. F. e,genera-ted in those portions of 5 which do duty as armature or workingco-nductors. The source of inde-pendent| E. M. F. 3l may conveniently bea secondary battery.

4In Fig. 4 the working circuit comprises the neutralizingwinding 3 andthe rotor winding 5 connectedin series relation by way of the workingbrushes 4, 6. The locally closed exciting circuit comprises the statorfield winding 9 connected in series with 5 by way of the excitingbrushes 7, 8 and along an axis displaced from that of 3. 'Ihe E. M. F.e, impressed on l1 is only about one-half of the 4terminal E. M. F. c,of the dynamo and is derived trom main 2 and a point of the fieldwinding 9. The other E. M. F. impressed on 11,'is e, and it is derived'from any desired independent source 31 and opposes el. Impressing on l1an E. M. F. smaller than the total working E. M. F. e, of the dynamopermits the capacity of .the source of the independentI tion of the maindynamo can be made to` var v in accordance with the variations of i', in11. Fig. 5 diagrammatically indicates how the stator 5G ot such a'dynamo can be constructed and h ow some of the windings an be locatedthereon. rl`he commuted winding 5 on the rotor is supposed to be of' the(iramme ring type and it isl assumed that the brushes 4, 7, S, beardirectly on that winding. rl`he coils undergoing commutation aretherefore situated immediately under there brushes.

To improve the connnutation, openings 50, 51, 52, 53 are provided in thestator 56 above the commuted coils. The stator windings can be locatedin slots `such as 54. A possible arrangement of the neutralizing winding3 and of the stator Held winding 9 is indicated in dotted lines. Theopenings ..30 and 52 corresponding to the coils ot' 5 being commutedunder the working brushes s'. ,t3 can be left out particularly when theneutralizing winding 3 is designed to have more ampere turns than thereare working ampere turns on 5.

Having fully described my invention, what I claim as new and desire tosecure by Letters Patent of the United States, is:

l. In a dynamo electric machine, a working circuit` and an excitingcircuit, an independentsource of E. M. F. and means tor producing ateaser flux along an axis displaced from the axis of the excitingcircuit, the magnitude of said teaser flux depending upon the diiferencebetween the independent E. M. F. and an E. M. F. derived from theworking circuit.

2. In a dynamo electric machine, the combination of a stator, a rotor, aworking circuit atl least partly disposed on the rotor, exciting brusheson the rotor, an independent source of M. F., and means for producing ateaser flux along an axis displaced from the axis of the excitingbrushes. the magnitude of said flux depending` upon the differencebetween the independent F.. M. F. and an E. M. F. taken from the workingcircuit.

3. In a dynamo electric machine, the coni- 'bination of a statorcarrying a .neutralizing winding, of a rotor, working brushes on therotor connected in series relation with the .neutralizilig winding,exciting brushes on neutralizing winding, a local exciting cir-- y E. M.F. and an E. M. F. derived from the working circuit. f

5. In a dynamo electric machine, a Working circuit and an excitingcircuit, a motorgenerator producing an independent E. M. F., saidmotor-generator being operated from the Working circuit, and means forproducing a teaser flux along an axisn displaced from the axis of theexciting circuit,

' the magnitude of said teaser'tlux depending upon the differencebetween the independent E. M. F. and an E. M. F. derived from theworking circuit.

6. In a dynamo electric machine, the combinationlwith a stator carryinga neutralizing winding, of a rotor, working brushes on the rotorconnected in series relation with the neutralizing winding, an excitingcircuit at least partly disposed on the rotor, a mo tor operated fromthe main working circuit, an auxiliarydynamo driven by said motor, ashunt field winding on the motor and one en the auxiliary dynamo, bothshunt Windings being fed from the working circuit, a series fieldwinding on the motor connected in series with the auxiliary dynamo, andmeans for producing a teaser flux along an axis displaced from the axisof the exciting circuit., the magnitude of said flux depending on thedifference between the E. M. F. derived from. the auxiliary dynamo andan E. M. I". derived from the rotor.

7 In a dynamo electric machine, the combination with a stator providedwith a neutralizing winding and a field winding displaced therefrom, ofa rotor, working brushes on the rotor connected in series relation withthe neutralizing winding, exciting brushes on the rotor connected 1nseries relation with the Iield Winding, an inde pendent source of E. M.F., and means for producing a teaser flux along an axis displaced fromthe axis of the exciting circuit, the magnitude of said flux dependingon the difference bet-Ween the independent E. M. F. and an E. M. Fderived from the working circuit.

9. In a dynamo electric machine, the combination with a stator carryinga neutralizing winding, of a rotor provided with a main Winding and anauxiliary winding, working brushes on said main rotor winding connectedin series relation with the neutralizing winding, exciting brush'es onthe main rotor winding, an independent source of E. M. F., and means forproducing a teaser flux along an axis displaced from the axis of theexciting brushes, the magnitude of said flux depending on the`difference between the independent E. M. F. and an E. M. F. derived fromthe rotor. l

10. InI a dynamo electric machine, the combination of a stator carryinga neutralizing Winding, a rotor provided with a main Winding and anauxiliary Windin workin brushes on each of said rotor win ings, botrotor windings being connected in series relation with the neutralizingWinding through said brushes, exciting brushes on one of the rotorwindings, an independent source of E. M. F., and means for producing ateaser flux along an axis displaced from the axis of the excitingbrushes, the magnitude of said flux' depending on the difference betweenthe Vindependent E. and an E. M. F. derived from the rotor.

In testimony whereof, I have hereunto set my hand and atixed my seal inthe presence of the two subscribing witnesses.

VALRE ALFRED rrNN. [n 8.1"'

Witnesses .f f

E. E. HUFFMAN, ELIZABETH BAILEY.

BIS`

